1. Field of the Invention
This invention relates to a small caliber penetrator projectile. More particularly, the penetrator projectile has a jacket enveloping tandemly aligned cores. A forward core is harder than a rearward core having a Brinell hardness of between about 20 and about 50.
2. Description of Related Art
Small caliber, under 0.5 inch diameter, penetrator projectiles are used by military forces worldwide. The United States and NATO military forces use vast quantities of M855 cartridges containing 62 grain penetrator bullets. The M855 bullets have two tandemly aligned cores enveloped by a brass jacket. A steel core is located in a nose section of the bullet and a 32 grain lead core is swaged into a rear section. Typically, the tail portion of the bullet is angled for ballistic stability and improved aerodynamic performance. At a total weight of 62 grains, the M855 bullet has the kinetic energy required to penetrate a 10 gage steel plate when fired from a distance of 600 meters.
Penetrator projectiles are disclosed in U.S. Pat. No. 740,914 to Platz and in U.S. Pat. No. 5,009,166 to Bilsbury et al. Both the Platz and the Bilsbury et al. patent are incorporated by reference in their entireties herein.
When the steel core impacts a target, compressive forces cause the trailing lead core to bulge. The bulge in the lead core has a diameter larger than the hole formed through the target by the steel penetrating core. This causes the lead core to deform on the surface of the target, transferring momentum to the target surface rather than to the steel core.
Many penetrator rounds are expended at target ranges in military drills. The large volume of lead contained within the projectiles makes environmental reclamation of the target ranges difficult and expensive.
There remains, therefore, a need for a projectile penetrator that is not subject to the disadvantages of the prior art.